CN111391041A

CN111391041A - Long-strip wood chip or bamboo chip woven laminated wood or board and preparation method thereof

Info

Publication number: CN111391041A
Application number: CN202010222837.6A
Authority: CN
Inventors: 王建和; 卫佩行; 徐英熙; 黄素涌
Original assignee: Ningbo Zhongjia Low Carbon New Technology Research Institute Co ltd; Southwest Forestry University
Current assignee: Ningbo Zhongjia Low Carbon New Technology Research Institute Co ltd; Southwest Forestry University
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2020-07-10
Anticipated expiration: 2040-03-26
Also published as: CN111391041B

Abstract

The long strip wood chip or bamboo chip woven laminated wood or board is composed of a plurality of layers of mutually overlapped and hot-pressed wood curtains or bamboo curtains, and the wood curtains or bamboo curtains are assembled by a plurality of narrow long strip wood chips or bamboo chips with the thickness of 0.2-4.0 inches and the modulus length of 1, 2, 4 feet or 8 feet. Has the advantages of high strength, light weight and good uniformity.

Description

Long-strip wood chip or bamboo chip woven laminated wood or board and preparation method thereof

Technical Field

The invention relates to the field of new concept materials, in particular to an engineering wood (bamboo) material, and specifically relates to a long wood chip or bamboo chip woven laminated wood or board and a preparation method thereof.

Background

At present, wood composite products are mainly classified into two major categories, non-veneer based and veneer based, the former includes Oriented Strand Board (OSB), oriented strand lumber (OS L), MDF and Particle Board (PB), and the latter includes veneer laminated lumber (L V L0), plywood, parallel strand lumber (PS L), laminated strand lumber (L S L). according to the end use, the products can be further classified into three categories, 1) structural composite lumber (SC L) such as L V L, PS L and OS L; 2) structural composite panels represented by OSB and plywood, and 3) non-structural composite panels including MDF and PB.

In contrast, plywood and a veneer-based composite such as L V L are made of veneers glued with glue, in order to allow sufficient contact between the veneers for bonding, only the surface irregularities such as roughness of the veneers need to be overcome, which is a lower compression, which facilitates the production of a lightweight product, one of the products between the two is PS L (or wood chips L S L) which is a column of veneer coated with phenolic resin, which is a high density wood strip, which is then compressed into a high density wood strip, which is a bar of high density, which is a high density wood strip.

The stiffness and strength of wood composites are the main properties of structural and industrial applications from a performance point of view, they are closely related to density however, to achieve the same level of stiffness and strength, veneer based and non-veneer based composites differ greatly in density, veneer based composites are generally lighter and more uniform in density, stiffness and strength, current Engineered Wood (EWP) products, particularly structural composite wood (SC L) comprise L V L0, PS L1 and OS L2, the basic units of which are veneers, long strands and flaked shavings respectively, L V L has a significant laminar structure compared to PS L3 and OS L4, enabling the product to be around 20-50% lighter and more uniform, L V L requires larger diameter grades, better quality logs and therefore its raw material utilization is lower (about 50-55%) although PS L and OS L can make full use of low quality raw materials, uniform forming to reduce density variations and raw material consumption is still a huge challenge to achieve a large change in density and a high PS L contact free of the desired stiffness and OS L unit.

In order to overcome the defects of single-board base and non-single-board base composite materials, a new concept of engineering wood needs to be invented, which not only can realize light weight, high strength and uniform performance, but also can fully utilize fast-growing wood or small-diameter logs, even wood waste.

Coleman in 1980 discloses a recombined wood and a preparation process and equipment thereof. The product is made by rolling and crushing natural wood or similar process into bundle, then drying, applying glue, pressurizing and curing. Although the process can be used with small, low-quality logs, the product requires special equipment in the unit preparation and formation of the mat, and the product does not have a distinct layered structure.

Barnes in 1998 disclosed a method of manufacturing composite lumber. The method comprises the following key steps: 1) producing wet veneer strips from fresh wood; 2) applying an adhesive to the wet veneer strips; 3) paving the glued veneer into a plate blank; 4) drying the plate blank; 5) and (4) hot-pressing the slab. This method is complicated in the control of drying and hot pressing.

Parker (2008) discloses a novel wood composite made from veneer strips. The product is prepared by the following steps: preparing raw wood, rotary cutting a veneer, drying the veneer, gluing the veneer, cutting the veneer into strips, assembling the strips, balancing the density, pretreating a plate blank, curing the plate blank and obtaining a final product. But the manufacturing process is more complicated, and the product can not realize light weight and high strength.

We weigh and Yadama (2008) developed a new engineered wood material, namely, laminated wood chip veneer composite (L SV). it uses the wood shavings of OSB to make into veneer which is used as single-layer board and then laminated to make the product, it needs to press single-layer veneer, its average density is 730kg/m³(Standard deviation 88.3 kg/m)³) The mean density of L SV was similar to commercial OS L but the former had a lower profile density distribution with the use of the Pinus koraiensis species, the MOE of L SV was between OSB and L V L and the mean value was 10204MPa and although L SV was comparable to OSB and OS L, it was higher in density, lower in material utilization and not a lightweight high strength material.

In the early 90 s of the last century, China developed a Bamboo Curtain Board (BCB). The starting point of this BCB is to utilize long and straight bamboo strips, and its preparation process is as follows: 1) because the bamboo is hollow and the fiber is straight, the bamboo tube can be split into long/narrow bamboo strips; 2) removing bamboo green and yellow from the bamboo strips; 3) splitting the bamboo wall of the bamboo strip into a plurality of bamboo splits with certain thickness along the length direction; 4) air-drying the bamboo splits to a target water content; 5) weaving the bamboo splits into a bamboo curtain by a machine or a hand (generally, the size of the bamboo curtain is 2440x1220mm, and the gap between the bamboo splits is usually small); 6) dipping the bamboo curtain with glue; 7) in the same fiberAssembling the impregnated bamboo curtain in the dimensional direction; 8) and (5) hot-press forming. Steps 1) to 5) can be performed by farmers or workers at home, and factories can purchase the bamboo curtains to manufacture the BCB. The product can replace steel or thick wood board and is mainly used for the occasions such as carriage bottom board, etc. The final product has a high strength, but a density of 750-1000kg/m³It is still heavy and does not give full play to the best performance of bamboo.

Disclosure of Invention

The present application addresses the above deficiencies of the prior art by providing a long strip wood or bamboo sheet woven laminated lumber or board having high strength, light weight, and good uniformity.

In order to solve the technical problem, the technical scheme adopted by the application is as follows: the woven laminated wood or bamboo board consists of several layers of superposed and hot pressed wooden curtain or bamboo curtain, which is assembled with several narrow long wooden sheets or bamboo sheets of 0.2-4.0 inch (5-100mm) thickness, 1, 2, 4, 8, etc. modulus and length.

By adopting the structure, the wood curtain or the bamboo curtain is assembled by a plurality of narrow long-strip wood chips or bamboo chips with the thickness of 0.2-4.0 inches (5-100mm), the modulus length of 1, 2, 4 feet or 8 feet and the like, so that the novel recombined engineering wood (bamboo) can be manufactured by fully utilizing small-diameter-grade and low-quality fast-growing logs and single boards or waste single boards and/or bamboos with random widths, the combination mode is flexible, and the utilization rate is high; meanwhile, as the wood curtain or the bamboo curtain is adopted as the base layer of each layer, the thickness of the board and the width of the gap between each narrow strip wood chip or bamboo chip can be flexibly adjusted, and the effects of reducing weight and improving strength are realized.

Preferably, the narrow long wood chips are obtained by rotary cutting or slicing a log into veneers having a thickness of 0.04-0.25 inch (about 1-6.5mm), forming the whole veneer, a veneer having a random width or a waste veneer, and cutting the veneers into a predetermined width. By adopting the mode, various wood defects which affect the strength of the board, such as knots, holes, decay and the like, can be effectively removed.

Preferably, the narrow long bamboo chips are: cutting bamboo into bamboo tubes with length of 2, 4, 8, 12, 16 or 20 feet, splitting the bamboo tubes into bamboo strips with width of 0.2-2.0 inch (5-50mm) along the circumferential direction, removing surf green and tabasheer, and splitting the bamboo strips into a plurality of long bamboo strips with thickness of 0.02-0.2 inch (0.5-5mm) along the length direction. By adopting the mode, the defects of the bamboo chips can be effectively removed, and the bonding performance of the rear panel is improved.

Preferably, the wood curtain or the bamboo curtain is formed by weaving a plurality of narrow strip wood chips or narrow strip bamboo chips at fixed intervals (gaps) along the width direction of the wood curtain or the bamboo curtain, and the interval is generally between 0.02 and 1 inch (0.5 and 25 mm); by adopting the mode, the weight of the product can be reduced, and the utilization rate of materials is improved; and the modular wooden curtain or bamboo curtain is helpful for drying, orientation and uniform pavement in subsequent drying and assembly, and is also helpful for evaporation of water vapor in hot pressing and chemical (corrosion prevention and the like) post-treatment of products.

Preferably, the wood curtain or the bamboo curtain is applied by dipping, roll coating or curtain coating, and the applied amount is 100-500 g/m (here, the area of the wood curtain or the bamboo curtain is taken as a reference), so that a good foundation is provided for subsequent hot pressing and sufficient adhesion between the wood curtain and the bamboo curtain.

Preferably, the overlapping mode of the multi-layer mutually overlapped and hot-pressed wood curtain or bamboo curtain is as follows: mixing wood curtains of different tree species or compounding the wood curtains and the bamboo curtains; in the thickness direction, the wood curtains and/or the bamboo curtains are staggered or arranged at intervals in the length direction, and the fixed intervals among the narrow strip wood sheets or the narrow strip bamboo sheets do not penetrate through the thickness direction (namely, after the multiple layers of wood curtains and/or bamboo curtains are overlapped, the fixed intervals on each wood curtain or bamboo curtain in each layer are shielded by the adjacent layers), so that the light weight, high strength and more uniform performance of the board can be realized.

The application also provides a preparation method of the strip wood chip or bamboo chip woven laminated timber or board, which comprises the following preparation steps:

(1) preparing narrow strip wood chips or bamboo chips:

wherein the narrow long wood chips are veneer with the thickness of 0.04-0.25 inch (about 1-6.5mm) according to the characteristics of the tree species and the logs, and then the whole veneer, the veneer with random width or the waste veneer after the rotary cutting or the slicing is cut to remove various growth defects such as knots, holes, decay and the like, so as to form the narrow long wood chips with the width of 0.2-4.0 inch (about 5-100 mm);

wherein, the narrow long bamboo chips are obtained by cutting bamboo into bamboo tubes with the length of 2, 4, 8, 12, 16 or 20 feet, splitting the bamboo tubes into bamboo strips with the width of 0.2-2.0 inches (5-50mm) along the circumference, removing bamboo green and tabasheer, and splitting the bamboo strips into a plurality of long bamboo chips with the thickness of 0.02-0.2 inches (0.5-5mm) along the length direction;

(2) drying and randomizing narrow strand wood or bamboo chips: drying to make the water content of long wood chips or bamboo chips uniform, controlling the water content between 3-10%, and simultaneously making the long wood chips or bamboo chips from different logs or bamboos and different parts uniformly dispersed and mixed;

(3) weaving into a curtain: weaving wood chips or bamboo chips with the same length (modulus) at fixed intervals (gaps) to form a modular wood curtain or a bamboo curtain;

(4) sizing: applying glue to the wood curtain or the bamboo curtain by adopting various coating modes such as dipping, roll coating, curtain coating and the like;

(5) and (3) drying: aging or drying the glued wood curtain or bamboo curtain again to obtain a modular wood curtain or bamboo curtain with the water content of 5-15%;

(6) assembling: according to the application and structure requirements of the product, different tree species wood curtains are mixed or the wood curtain and the bamboo curtain are compounded; in the thickness direction, the wood curtain and/or the bamboo curtain are staggered or arranged at intervals according to the length of the wood curtain and/or the bamboo curtain, so that the gap does not penetrate through the wood curtain and/or the bamboo curtain in the thickness direction;

(7) hot pressing: and (4) carrying out hot pressing on the product assembled in the step (6), wherein the hot pressing conditions are as follows: the temperature is 140 ℃ and the pressure is 175 ℃ and 350psi (1.2-2.4MPa), the compressibility is 5-25%, and the time is determined by the thickness of the plate.

Preferably, the narrow strip strands of step (1) are cut to eliminate any potentially strength-reducing defects in the veneer, such as knots, holes and decay, while taking full advantage of the maximum allowable length of the veneer.

Preferably, the step (2) of simultaneously dispersing and mixing the long strands or bamboo chips from different logs or bamboos and different parts uniformly can make the recombined product more uniform, thereby reducing the density variation of the final product.

Preferably, the knitting in step (3) may be glue thread, cotton thread or other knitting thread.

Preferably, the modular wood or bamboo curtain described in step (3) may have a size of 2 × 4 feet, 2 × 8 feet, 4 × 4 feet, 4 × 8 feet or 8 × 4 feet, 12 × 4 feet, 16 × 4 feet, etc.

Preferably, the gap of the fixed interval (gap or slit) between the adjacent wood chips or bamboo chips in the modular wood curtain or bamboo curtain in the step (3) is generally 0.02-1 inch (0.5-25 mm); the arrangement can reduce the weight of the product and improve the utilization rate of materials. Furthermore, the modular wooden or bamboo curtain facilitates drying, orientation and uniform laying during subsequent drying and assembly, as well as evaporation of water vapour during hot pressing and chemical (corrosion protection, etc.) post-treatment of the product.

Preferably, the amount of sizing in step (4) is generally 100-500 g/m (here, the area of the wood or bamboo curtain is taken as a reference).

Preferably, the hot pressing in the step (7) can be performed by a conventional plywood press or a L V L press by a similar process to ensure the curing of the adhesive, compared with OS L and PS L, the novel engineered wood (bamboo) can use lower pressing temperature and pressure, the temperature of the hot pressing process is 140-.

The application has the advantages and beneficial effects that:

1. the invention can realize the production of novel recombined engineering wood (bamboo) by using small-diameter-grade and low-quality fast-growing logs and single boards with random widths or waste single boards and/or bamboos, can fully utilize domestic rich fast-growing tree species and bamboo resources, and has high utilization rate of raw materials and low production cost; the final product is green and environment-friendly, can be sustained, has light weight, high strength and stable size and performance, and can be widely used in various building materials, home decoration, industrial application and other occasions.

2. The method for manufacturing the light high-strength engineering wood (bamboo) disclosed by the invention has not been reported yet, and has no commercial application yet. The advantage of using a wooden curtain with a length of 1, 2, 4 or 8 feet module is that it can be fully utilized: a) small diameter/low mass fast-growing tree species logs; b) random single plates or waste single plates are utilized to improve the material utilization rate and the flexibility of product design.

3. The novel woven wood curtain and the novel modular assembly product structure provided by the invention enable the product to be lighter, higher in strength and more uniform in performance, and the novel woven wood curtain and the novel modular assembly product structure also allow the wood (bamboo) curtain to have higher water content after being dried, which means that more energy is not required for drying raw materials, and the disclosed product and the manufacturing method can be embedded into the existing plywood and L V L production lines by adding industrial weaving equipment or improving the currently used veneer splicing equipment.

4. The product prepared by the invention also has the following advantages that 1) the strip wood (bamboo) sheet can realize accurate and complete orientation, 2) the adjustment of the product size is simplified by using the size of the modularized wood (bamboo) curtain, the paving forming and the product density distribution are very uniform, 3) the pressing temperature and pressure are lower, generally 140-.

Drawings

FIG. 1 is a schematic view of the present application showing different dimensional specifications of a modular wood or bamboo curtain;

as shown, including 2 × 4 feet, 4 × 4 feet, 2 × 8 feet, and 4 × 8 feet.

FIG. 2 is a schematic structural diagram of a typical engineered wood (or bamboo) board of the present application (9 layers are taken as an example, co-directional paving); as shown in the figure: a is the staggered arrangement of the surface layer slit (slit)/the inner layer slit (namely the slit of the adjacent wood chip or bamboo chip in the wood chip curtain or bamboo chip curtain of the upper and lower surface layers is small, the slit of the wood chip curtain or bamboo chip curtain with large slit is staggered in the middle, and the slits of the multiple layers of wood chip curtains or bamboo chip curtains with large slits are staggered), and b is the spaced arrangement of the slit layer and the slit layer (namely one layer of small slit layer and one layer of large slit layer are alternately superposed).

Fig. 3 is a schematic illustration of the inner layer structure of a 4x8 foot reconstituted engineered wood (or bamboo) plank of the present application.

Fig. 4 a schematic view of the transverse (cross) layer structure of a 4x8 foot reconstituted engineered wood (or bamboo) plank of the present application.

Fig. 5 is a flow chart of the production process of engineered wood SS L of the present application, wherein a is the strand randomization and the wood curtain assembly, and b is the hot press and SS L product.

FIG. 6 is a schematic structural diagram of a sheet product according to the present application.

Fig. 7 is a schematic view of the structure of the wood or bamboo curtain of the present application.

Detailed Description

The present application is described in further detail below by way of specific examples, but the present application is not limited to only the following examples.

In the embodiment of the present application, the wood curtain or the bamboo curtain has small gaps formed at intervals (thin gaps), has large gaps formed at intervals, and has no specific specified range when the large gaps and the small gaps are compared relatively. As shown in fig. 6, the upper and lower surface layers are bamboo curtains or wood curtains 1 with small gaps or fine gaps, the middle layer is bamboo curtains or wood curtains with large gaps, the middle bamboo curtains or wood curtains with large gaps, and the gaps of the adjacent layers are staggered, so as to improve the strength of the whole plate.

As shown in fig. 1, 2 and 6, the long strip wood or bamboo chip woven laminated timber or board is composed of a plurality of layers of mutually overlapped and hot pressed wood curtains or bamboo curtains 1, and the wood curtains or bamboo curtains are assembled by a plurality of narrow long strip wood or bamboo chips 2 with the thickness of 0.2-4.0 inches (5-100mm) and the module length of 1, 2, 4 feet or 8 feet, etc.

By adopting the structure, the wood curtain or the bamboo curtain is assembled by a plurality of narrow long-strip wood chips or bamboo chips with the thickness of 0.2-4.0 inches (5-100mm), the modulus length of 1, 2, 4 feet or 8 feet and the like, so that the novel recombined engineering wood (bamboo) can be manufactured by fully utilizing small-diameter-grade and low-quality fast-growing logs and single boards or waste single boards and/or bamboos with random widths, the combination mode is flexible, and the utilization rate is high; meanwhile, as the wood curtain or the bamboo curtain is adopted as the base layer of each layer, the thickness of the board and the width of the gap between each narrow strip wood chip or bamboo chip can be flexibly adjusted, and the effects of reducing weight and improving strength are realized. In addition, as can be seen from fig. 2, the gaps between the wood sheets or the bamboo sheets of the mutually overlapped and hot-pressed wood curtains or bamboo curtains on each layer are large or small, different wood curtains or bamboo curtains formed by different gaps can be mutually overlapped, the adjustment is flexible and convenient, and the wood curtains or bamboo curtains in different gaps are mutually overlapped to reinforce the strength and toughness of the whole plate, so that the plate is more stable.

The narrow and long wood chip is prepared from the following raw materials in parts by weight: the raw wood, the veneer with random width or the waste veneer is cut into the veneer with the thickness of 0.04-0.25 inch (about 1-6.5mm) by rotary cutting or slicing, and the whole veneer, the veneer with random width or the waste veneer after the rotary cutting or the slicing is cut into the specified width to obtain the veneer. When cutting, various wood growth defects such as knots, holes, decay and the like which affect the strength of the product are removed.

The application the long and narrow bamboo chips are: cutting bamboo into bamboo tubes with length of 2, 4, 8, 12, 16 or 20 feet, splitting the bamboo tubes into bamboo strips with width of 0.2-2.0 inch (5-50mm) along the circumferential direction, removing surf green and tabasheer, and splitting the bamboo strips into a plurality of long bamboo strips with thickness of 0.02-0.2 inch (0.5-5mm) along the length direction. By adopting the mode, the defects of the bamboo chips can be effectively removed, and the performance of the final board is improved.

As shown in fig. 7: the wood curtain or the bamboo curtain is formed by weaving a plurality of narrow strip wood chips or narrow strip bamboo chips along the width direction thereof at fixed intervals d (gaps), wherein the interval is generally 0.02-1 inch (0.5-25 mm); by adopting the mode, the weight of the product can be reduced, and the utilization rate of materials is improved; and the modular wooden curtain or bamboo curtain is helpful for drying, orientation and uniform pavement in subsequent drying and assembly, and is also helpful for evaporation of water vapor in hot pressing and chemical (corrosion prevention and the like) post-treatment of products.

The wood curtain or the bamboo curtain is applied by dipping, roll coating or curtain coating, the application amount is 100-500 g/m (the area of the wood curtain or the bamboo curtain is taken as a reference), and a good foundation is provided for subsequent hot pressing and sufficient adhesion between the wood curtain and the bamboo curtain.

As shown in fig. 2, 5 and 6, the overlapping mode of the multi-layer mutually overlapped and hot pressed wood curtain or bamboo curtain is as follows: mixing wood curtains of different tree species or compounding the wood curtains and the bamboo curtains; in the thickness direction, the wood curtains and/or the bamboo curtains are staggered or arranged at intervals in the length direction, and the fixed intervals among the narrow strip wood sheets or the narrow strip bamboo sheets do not penetrate through the thickness direction (namely, after the multiple layers of wood curtains and/or bamboo curtains are overlapped, the fixed intervals on each wood curtain or bamboo curtain in each layer are shielded by the adjacent layers), so that the light weight, high strength and more uniform performance of the board can be realized.

Example 1 Pilot production and comparison of Strength Properties of New concept engineered Wood SS L

Dried 200 sheets of 1/8 inch thick, 4 foot long, random width twisted leaf pine veneers were purchased from a plywood factory western Canada, having a moisture content of about 5% and an average density of 460kg/m³Cutting about 1500 single-board strip wood chips (the width is 1 inch) with the specification of 36x1.0x0.125 inches after removing defects such as knots and the like, then uniformly mixing, weaving a single-board wood curtain with the size of 36x24x0.125 inches by using a cotton thread hand weaving mode, wherein each single-board wood curtain is formed by sewing 24 random single-board strip wood chips, co-weaving to generate 50 single-board wood curtains for producing 16 layers of woven engineering wood (SS L), the paving direction of each layer is the same (similar to L V L), in a pilot test, three woven engineering wood (SS L) with the specification of 36x18x0.125 inches are co-produced, as a control, the same batch of twisted-leaf pine single boards are dried and cut into 50 single boards with the size of 36x18x0.125 inches, the production process parameters and the solid content of two boards used for producing three 16 layers of single-board laminated wood (SS L V L), SS L and L V L are completely the same, the glue-coated glue amount is 230g, and the glue coating roller is used for gluing²(ii) a After single-side gluing, the grain smoothing is carried outAnd (3) paving in the same direction, aging for 2 minutes, and then carrying out hot pressing, wherein the hot pressing temperature is 155 ℃, the pressure is 300psi (about 2.0MPa), the hot pressing time is 30min, the target thickness is 1.75 inches, and the compression ratio of the final plate blank is about 12.5 percent, and fig. 5 shows the production process of the new concept engineering wood SS L.

After each woven engineered wood (SS L) and a comparison group laminated veneer lumber (L V L) are stacked for 7 days after being hot pressed, 4 flat bending test pieces and 4 side bending test pieces are respectively cut, and 12 test pieces are generated for each plate to test the bending resistance, and the physical and mechanical properties of SS L, comparison L V L and commercial OS L are shown in Table 1 and Table 2.

TABLE 1 comparison of the results of the lateral bending

Note that the numbers in brackets are the standard deviation of the density of the test sample plates;

commercial OS L at 1.7Mpsi MOE design value;

commercial OS L at 1.3Mpsi MOE design value.

Table 1 shows a comparison of the panel densities for four structural composite wood (SC L) products (i.e., SS L, controls 850V L, 1.7E OS L, and 1.3E OS L). it can be seen that the density and variability of SS L are lowest, followed by L V L, 1.7E OS L, and 1.3E OS L. the results show that the side bend MOE and MOR of SS L are the least variable, the highest in specific stiffness and strength, and second in L V L and OS L. the side bend MOE and MOR of SS L are consistently higher than L V L, which may be due to the uniform mixing and variability of the individual slats in the wood curtain.

TABLE 2 comparison of Flat bending results

As can be seen from Table 2, SS L has the highest mean and MOR for flat bending, and the highest specific stiffness and strength, followed by L V L, 1.7E OS L, and 1.3E OS L. compared to the side bending results, both the mean and standard deviation for flat bending MOE and MOR for SS L are higher.

In summary, SS L has higher bending MOE than L V L for both side bending and flat bending primary uses and mor.ss L has higher specific strength than 1.7E OS L and therefore has better competitive advantage than 1.7E OS L although it has about 27% reduction in density at the same density and same manufacturing parameters.

Depending on the end use, higher than normal compression may be used to achieve higher product stiffness and strength. The new engineered wood can also be made to achieve its highest cost performance by using mixed tree species, i.e. tree species with high stiffness and good appearance are put on the outer layer. By using a resin impregnated wood curtain, the performance and durability of the product can be further improved. Therefore, the new concept engineering wood (bamboo) has lighter weight, stronger strength and uniformity, can greatly contribute to reducing the production cost and improving the utilization rate of raw materials, and has remarkable economic benefit and social benefit.

Claims

1. A long strip wood or bamboo sheet woven laminated lumber or board, characterized in that: the woven laminated lumber or board is composed of a plurality of layers of mutually overlapped and hot-pressed wood curtains or bamboo curtains, and the wood curtains or bamboo curtains are assembled by a plurality of narrow strip wood chips or bamboo chips with the thickness of 0.2-4.0 inches and the modulus length of 1, 2, 4 feet or 8 feet.

2. The long strand wood or bamboo sheet woven laminate lumber or board as claimed in claim 1, wherein:

the narrow long wood chips are obtained by rotary cutting or slicing logs into veneers with the thickness of 0.04-0.25 inch, and then cutting the obtained whole veneer, veneer with random width or waste veneer into specified width;

the narrow long bamboo chips are as follows: cutting bamboo into bamboo tubes with the length of 2, 4, 8, 12, 16 or 20 feet, splitting the bamboo tubes into bamboo strips with the width of 0.2-2.0 inches along the circumferential direction, removing green and tabasheer, and splitting the bamboo strips into a plurality of long bamboo chips with the thickness of 0.02-0.2 inches along the length direction.

3. The long strand wood or bamboo sheet woven laminate lumber or board as claimed in claim 1, wherein:

the wood curtain or the bamboo curtain is formed by weaving a plurality of narrow strip wood chips or narrow strip bamboo chips at fixed intervals along the width direction of the wood curtain or the bamboo curtain, and the interval is generally between 0.02 and 1 inch;

the outer surface sizing is carried out on the wood curtain or the bamboo curtain in a dipping or roll coating or curtain coating mode, and the sizing amount is 100-500 g/per square meter.

4. The long strand wood or bamboo sheet woven laminate lumber or board as claimed in claim 1, wherein: the superposition mode of the multilayer mutually superposed hot-pressed wood curtain or bamboo curtain is as follows: mixing wood curtains of different tree species or compounding the wood curtains and the bamboo curtains; the narrow strip wood chips or the narrow strip bamboo chips are arranged in the thickness direction in a staggered or spaced mode along the length direction of the wood curtain and/or the bamboo curtain, and the fixed intervals among the narrow strip wood chips or the narrow strip bamboo chips do not penetrate through the narrow strip wood chips or the narrow strip bamboo chips along the thickness direction.

5. A method for preparing a long strip wood chip or bamboo chip woven laminated timber or board is characterized in that: the preparation method comprises the following steps:

(1) preparing narrow long wood chips or bamboo chips, (2) drying and randomizing the narrow long wood chips or bamboo chips, (3) weaving into curtains, (4) gluing, (5) drying, (6) assembling and (7) hot pressing.

6. The method for producing long strand wood or bamboo sheet woven laminated lumber or board as claimed in claim 5, wherein: the preparation method comprises the following steps:

(1) preparing narrow strip wood chips or bamboo chips:

wherein, the narrow long wood chips are cut into veneers with the thickness of 0.04 to 0.25 inch by rotary cutting or slicing according to the characteristics of the tree species and the logs, and then the whole veneer, the veneer with random width or the waste veneer after the rotary cutting or the slicing is cut into the narrow long wood chips with the width of 0.2 to 4.0 inches;

the narrow long bamboo chips are obtained by cutting bamboo into bamboo tubes with the length of 2, 4, 8, 12, 16 or 20 feet, splitting the bamboo tubes into bamboo strips with the width of 0.2-2.0 inches along the circumference, removing green and yellow bamboos, and splitting the bamboo strips into a plurality of long bamboo chips with the thickness of 0.02-0.2 inches along the length direction;

(3) weaving into a curtain: weaving the wood chips or the bamboo chips with the same length according to a fixed interval to form a modular wood curtain or a bamboo curtain;

(7) hot pressing: and (4) carrying out hot pressing on the product assembled in the step (6), wherein the hot pressing conditions are as follows: the temperature is 140 ℃ and the pressure is 175 ℃ and 350psi, the compressibility is 5-25%, and the time is determined by the thickness of the plate.

7. The method for producing long strand wood or bamboo sheet woven laminated lumber or board as claimed in claim 6, wherein: the narrow strip wood chips in the step (1) need to be cut to eliminate any strength reduction defect on the veneer; in the step (2), the wood chips or bamboo chips from different logs or bamboos and the long strips from different parts are uniformly dispersed and mixed.

8. The method of claim 6 wherein the strand wood or bamboo chips are woven into the laminate lumber or board, the step (3) wherein the woven strand is glued, cotton or other woven strands, the step (3) wherein the modular mat or curtain is of the type 2 × 4 feet, 2 × 8 feet, 4 × 4 feet, 4 × 8 feet or 8 × 4 feet, 12 × 4 feet, 16 × 4 feet, and the step (3) wherein the spacing between adjacent strands or sheets of the modular mat or curtain is generally between 0.02 and 1 inch.

9. The method for producing long strand wood or bamboo sheet woven laminated lumber or board as claimed in claim 6, wherein: the amount of sizing in step (4) is 100-500 g/m.

10. The method for producing long strand wood or bamboo sheet woven laminated lumber or board as claimed in claim 6, wherein: the temperature of the hot pressing process in the step (7) is 140-.